Starch of pellets, pebbles, or nodules and process of making same.



ALEXANDER nANnERsoN; or CHICAGO, ILLINOIS.

STAROH PELLETS, PEBBLES,OR NODULES AND PROCESS OF MAKING SAME.

- Specification of Letters Patent.

Patented Aug. 20, 1912.

Application filed August 31,1906. Serial No. 332,807.

To all whom it may concern:

Be it knownthat I, ALEXANDER P. ANDER- SON, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinois, have invented new and the generic invention set forthgin myapplidescribed in my cation filed contemporaneously herewlth, Serial No.332,804.

"It is the object of my invention to provide a rapid, economical andeflicient process of treating starch in the powdered condition toproduce a new and useful product which may be used for food and otherpurposes; also, to produce a product itself which may be formed by theprocess referred to and having new and useful properties hereinafterdescribed.

The above process may be carried out and the new product produced bymeans of the apparatus shown in the accompanying drawing, or by theapparatus shown and co-pending application, filed August 3, 1906, SerialNo. 329,030.

In these drawings, Figure 1 is a side view of the piping together with alongitudinal sectional elevation of the drum-support in the oven, thelatter being indicated in dotted lines; Fig. 2 is a rear end view of thearrangement shown in Fig. 1; Fig. 3 shows the drum in charging anddischarging positions, the latter position being indicated in dottedlines; Fig. 4 is a sectional view of the rear end of the drum; and, Fig.5 is a section of the drum on the line 5-5 of Fig. 4.

The raw material to be treated is put into a drum 2, mounted upon asuitable car capable of being rolled about and brought to the variousparts of the apparatus for handling. The car consists of two sidemembers 3, 3, having a trunnion 4 extending therebetween at the rearend; a shaft or axle 5 connects the forward ends of said members. SmallWheels or rollers 6 are mounted outside of the members 3, upon theprojecting ends of trunnion 4 and shaft 5. The cars run on a track 7within the oven, consisting of four rails fastened to the inside of thecage 8. At each end of the oven isa ring 9 having teeth outside forminga gear, which meshes with another gear 10 adapted to rotate the cage.The gears 10 and rollers 11 support the cage and inclosed drum, inaddition to causing rotation thereof by any suitable power applied toone of their supporting shafts outside of the oven.

After the drum has been run into the oven, a steam-connection is made at12, thus admitting steam to the flattened pipe 13 inside of the drum.The steam escapes into the drum through numerous holes 14.- in the pipe,said holes becoming more frequent in proportion to the drop in pressureas the steam advances.

By means of the gears 9 and 10 the cage containing the drum is rotatedslowly during the heating. Rotation ispermitted by the stufiing box 12which at the same time maintains the steam-connection. The arrangementof the piping shown is as folbe closed and 15 opened, whereby thepressure escapes into the atmosphere. Thus, by propervalve-manipulation, the conditions of pressure and temperature in thedrum may be regulated and controlled absolutely within the desiredlimits. Itwill be understood that the oven is heated by any suitable ordesired means, as, for example, by gas.

The lid 18 of the drum is clamped tightly closed, a suitable soft-metalgasket being provided to cause an air-tight connection, when the drum isin the horizontal position in its frame. In order that the heating maynot unseal the lid, I prefer to make the drum of bronze or some materialhaving a higher coefficient of expansion than the side members of theframe.

To remove the drum from the oven after the heating, valve 15 is closed,the drum is disconnected at 12, and is. run out of the oven to a raisingand lowering mechanism suitably connected with the drum through the arm17. By means of this mechanism the drum is lowered about the shaft 4 asa pivot, as indicated in dotted lines in Fig. 3.

The lid, 18, previously held shut by the roller'19, suddenly flies openfrom internal pressure, if pressure there be, and the contents aredischarged assisted by gravity.

In charging, the drum is raised by the same arm or screw ,17 until ittilts upwardly, when the material to be treated may be fed into thedrum.

By means of the apparatus just described, which is preferred forcommercial purposes, it is convenient and practicable to subject thematerial in the drum or cylinder to any degree of heat or pressure, aswell as to the desired agitation or tumbling action.

In the preferred manner of carrying out the process, I take starch whichcontains about 35 to 45% of moisture. When air-dry starch is used, themoisture percentage of which is known, it is necessary to add water toit, so as to bring its moisture up to that needed. Such water may beadded by any convenient method, as by spraying, while the starch isbeing stirred. It is apparent that when starch contains from 35 to 45%ofmoisture, it contains'no lumps like those present in eitherpearlstarch or in the ordinary lump starches, it being well known that lumpstarch contains a smaller percentage of moisture, being about air-dry.Starch, therefore, containing about -to 45% of I moisture contains nolumps since the water has broken down the lumps that were present in thestarch before the water was added, provided the water was fullydistributed. Freshly made starch which has been freed from a sufficientamount" of its water to bring its moisture percentage down to about 35to may be used instead of adding the water to air-dry starch, asmentioned.

Enough of the starch, comminuted or in a reduced state of subdivision,is now put into the rotatable drum to. fill the same about one-half tothree-fourths. The drum is then closed air-tight, and the treatmentbegun by heating the drum while it is kept rotating preferably in ahorizontal position. The drum is heated by any suitable means, asbyplacing it inside of the oven, or it may have a steam-jacket aroundit, in which case suflicient heat can be obtained by admitting steam ata sufficient temperature to this jacket. The temperature to which thedrum is heated is about 150 to 200 C.

' .On account of the rotation of the drum, the starch during thetreatment is continually tumbling upon itself, andits temperature keptincreasing. When this tempera ture reaches thegelatinization-temperature of the starch, say about to'80 C., the starchgranules become sticky, and a few coalesce together, and form a startingpoint or nucleus around which other starch gran ules become attached assoon as they are ules do not become sticky at the same time, since onaccount of their varying sizes they are not all of them at the sametemperature at the same time, especially when the starch under treatmentfirst reaches its gelatinization-temperature of about 70 to 80 C.

I have found that almost an innumerable number of these nuclei orcenters form throughout the starchy mass under treat ment, andapparently at substantially the same time, so that they all begin theirgrowth by the accretion of the still remaining loose starch, therebyincreasing in size in their tumbling or rolling about, at about the samerate. So that when they have gathered up all of the loose starch, theyare about the same size, usually varying from the size of an ordinarypin-head to that of a grain of wheat. In either form, the lumps or ballsare nodular, pellet or pebble-like, due to their method of growth by theaccret1on of particles on their surfaces while tumbling'or rolling.

The formation of the starch into pebble lumps, as explained, occurs at acomparatively low temperature of the starch, and is completed by thetime this temperature reaches 100 C. or slightly higher. Atthistemperature, or soon after, the pressure gage on the drum begins to showpressure, due to the formation into steam of a part of the moisture inthe starch. This steam increases in temperature and quantity with theincreasing temperature of the drum, and the contained starch is now inthe form of lumps or pebbles. The steam-atmosphere thus formed inside ofthe drum and surrounding the tumbli ng lumps is substantially saturatedsteam, which is at a greater temperature than the starch lumps. Hence,condensation of the steam on the lumps takes places, making theirsurfaces wet with free water. lump of starch containing, as it does,about 35 to 45% of moisture cannot hold all of this moisture withinitself when at this temperature, so that some of the moisture which isleft after that which has formed into steam must of necessity form onthe surface of the lumps as free water or sweat.

It has been. found that the surfaces of the lumps as soon as they haveformed and gatheredup all of the loose starch, as above explained, aresmooth and considerably hardened. So that as soon as they becomesurrounded with the steam atmosphere and condensation of steam takesplace on their surfaces, the-yare sufliciently hard and their surfacessufficiently gelatinized, as well as so wet with free water or sweat,that they are what may be termed slippery, and for this reason do notstick together, but continue tumbling separately and thereby polish eachother. It is apparent that the moisture thus formedand present on thesurfaces of It follows also that the whole percentage of moisturepresent in the starch,

I by leaving falls to zero.

gelatinization to the extent of actual fusion of the starch granulestakes place throughout the whole lump and therefore causes a hard, hornyand insoluble starch-lump. The

.treatment is continued until. a pressure of about 10 to 25 pounds persquare inch has developed inside of the drum, the total time requiredfor treatment up to this pressure being about one and one-half to twohours. The blow-off valve of the drum is now opened, partially at first,and then fully, and the blowing off continued until the pressure Thedrum is then opened, and the starch lumps taken out. As they come out ofthe drum they still contain about 25 to 30% of moisture, They aretherefore spread out to dry in the sun or kiln dried by ordinarymethods, until the lumps are in air-dry condition.

I have found that although it is preferable to use some pressure inmaking the product, as above described it may be made the blow-ofi valveof the drum open so as to allow the steam formed by the heating of thestarch to escape slowly through it, and by subjecting the drum to ahigher heat than that mentioned above, that is, to about 250 C. Infollowing this method, the product can be made in about one hour andthirty minutes instead of two hours, as stated above. The other stepsmay remain the same, except that the final blowofi is of courseunnecessary.

The product thus produced consists of dry pebble-like grains in whichall of the starch has been uniformly gelatinized and to such an extentthat the whole grain has been converted into a hard, horny pebbled lumpstarch having an unbroken glazed and polished surface. The product has ahomogeneous structure throughout, but due to its growth as made-by theabove process by the accretion of starch on its surface when tumbling orrolling, concentric layers more or less distinct, especially whenheated, can be seen. That is, its starch has been gelatinized to thesame extent and carried so far that a more or less complete fusion orcoalescence of the granules has taken place; the lumps therefore do notbreak down or dissolve in either cold or boiling water. When placed inwater, they absorb it slowly, and when boiled they swell considerably,becoming soft, semi-transparent and jelly-like, still, however,retaining their, shape, and being soft enough to be easily crushed bythe fingers. In this jelly-like condition they may be use as a food bysweetening, or by being made into puddings, etc. Instead of using waterthe lumps may be boiled with mill". A still further use of the productis that it can be swelled or pufi'ed in a substantially air-drycondition, that is, when it contains about 15 to 25% of moisture, bysubjecting it'to the treatment for swelling or putting described in thepreferred process of my copending application Serial No. 332,805 filedAugust 31, 1906, and finally pulverizing and preferably bolting theswelled product thus obtained. A new starch powder thus results which issubstantially the same as that described in said application.

Inasmuch as it is not necessary to have the drum air-tight during thetreatment of the starch, as hereinbefore fully explained, I would haveit understood that by the term closed receptacle, appearing in theappended claims, I mean a receptacle which may or may not be closedair-tight, according as it is desired to carry out the process with orwithout extreme pressure within the receptacle,-all as previously setforth.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. The process disclosed, which consists in heating comminuted starchcontaining about 35 to 45 per cent. moisture in a closed receptacle to asuflicient temperature to start gelatinization, whereby adheslve nucleior centers are formed, meanwhile subjecting the material to a tumblingaction, and then continuing the heating and tumbling until the mass hasbeen substantially completely gelatinized and substantially all of theloose material has been gathered up by the nuclei or centers intopellet-like lumps.

2. The process disclosed, which consists in heating and tumblingcomminuted starch containin about 35 to 45 per cent. moisture in a closereceptacle to a sufiicient temperature to start gelatinization, wherebyadhesive nuclei or centers are formed which, due to the tumbling action,gather up the loose materialinto pellet-like lumps, the heat beingcontinued to the degree necessary to effect uniform gelatinizationthroughout the starch, and then drying the product to a substantiallyair-dry condition.

3. The process disclosed, which consists in heating and tumblingcomminuted starch containing about 35 to 45 per cent. moisture in aclosed receptacle and to a temperature necessary to bring aboutgelatinization of the starch-granules, whereby the same form adhesivenuclei or centers which, due to the tumbling action, gather up the loosematerial into pellet-like lumps, the heating being continued and raisedto a degree necessary to practically completely gelatinize the starch,and then drying the product to a substantially air-dry condition;

4. The process disclosed, which consists in tumbling comminuted starchcontaining about 35 to 45 per cent. moisture in a closed receptacle andheating the same to a temperature sufficient to start gelatinizationthereof, whereby adhesive nuclei or centers.

rial is gathered up by the nuclei into gelatinized pellet-like lumps,and then slowly reducing the pressure.

, 5. The process disclosed, which consists in heating in a closedreceptaclecomminuted starch containing about 35 to A5 per cent.moisture, while subjecting the same to a tumbling action, to atemperature sufiicient to start gelatinization of the starch, wherebysticky nuclei or centers are formed, then continuing the heating andtumbling until a pressure of about M2 to pounds per square inch hasdeveloped within the receptacle to completely gelatinize the starch andwhereby, due to the tumbling act-ion, substantially all of the loosematerial is v gathered up by the nuclei into gelatinized pellet-likelumps, then slowly reducing the pressure, and then drying the product toa substantially air-dry condition.

6. As a new article of manufacture, a starch-product consisting ofuniformly gelatinized pellet-like lumps, hard and horny throughout andhaving unbroken glazed or polished surfaces.

7. As a new article of manufacture, a starch-product consisting of hardand horny pellet-like lumps in which the starch is uniformly gelatinizedthroughout the lumps.

8. As an article of manufacture, a starchproduct made from ordinarystarch consisting of uniformly gelatinized pellet-like lumps which arehard and horny throughout and which, when'placed in water, absorb itslowly, at the same time swelling and becoming soft and translucent,while retaining their original shapes.

In witness whereof, I have hereunto subscribed my name in the presenceof two witnesses.

ALEXANDER P. ANDERSON. Witnesses:

J JAY SMITH, JAMES RmEoU'T.

